1. Field of the Invention
This invention relates to a camera multi-program control device which indicates an apposite program according to the aperture value and the focal length of a lens or changes an inapposite program to an apposite program.
2. Description of the Prior Art
Multi-mode automatic exposure control cameras of the kind permitting selection of various exposure control modes such as a shutter speed preference mode, an aperture preference mode and a programed mode have been in use. In cameras of this kind, letters or marks have generally been used for indicating the exposure control modes selected at an operation part or within a view finder. However, such letters and marks are inconvenient, particularly for beginners who are unable to select an apposite aperture value or a shutter time value for obtaining a picture image effect depending on the depth of focus or the difference in shutter time or who do not know the interrelation of the aperture value, shutter time, film sensitivity and brightness of the object to be photographed since they can hardly understand the relation of an obtainable picture image effect to the aperture value or shutter time value. The indication of a selected mode with a mere letter or mark does not readily inform the user of a combination of shutter time and an aperture value required for a desired effect on the picture to be taken. Besides, in some lenses, aperture values such as a maximum aperture F-number, a minimum aperture or a fixed aperture are limited and they differ in focal length. Therefore, the kinds of lenses capable of giving a certain picture image effect is limited. The arrangement of the prior art thus has been not only difficult for beginners to understand but has also limited the possible range of photography operations.
It is an object ot the present invention to provide a multi-program control camera which permits selection of various exposure control modes and gives a warning when a desired picture image effect is hardly obtainable by the selected exposure control mode so that an apposite exposure control mode can be selected without difficulty to eliminate the above shortcoming of the prior art arrangement.
It is another object of the invention to provide a multi-program control camera which permits selection of various exposure control modes and which automatically shifts a selected exposure control mode to an apposite exposure control mode when a desired picture image effect is hardly obtainable by the selected mode, so that a standardized photograph can be taken without fail.
These and further objects and features of the invention will become apparent from the following detailed description of preferred embodiments thereof taken in connection with the accompanying drawings.